Heatpump problem

I recently had a leak in my evaporator coil. A professional service man replaced the evaporator and the next day the unit wouldn't work. I called him back and he said that the inside coil that he replaced had an orifice and the outside unit has an expansion valve. He had to reset a pressure switch outside to get the unit to work on AC. The problem was the inside unit needs an expansion valve which he will come back to install. He said to not use it on heat until he comes back to install the expansion valve. I suspect he used an coil inside for an AC unit not a heat pump. Can he actually fix the unit by replacing the orifice with an expansion valve. Is this acceptable, or is he trying to screw me?